Discuss modifications you have done or plan to do to your Dreamcast or any other hardware, or discuss devices you want to build. If your console does not work or is acting up, ask about fixing it in here.
I'm looking forward to build a "coders cable" (USB <-> Dreamcast Serial) .
I've come across mr. henzenmann 's blog post, and while i wait for the quote from siphec regarding their usb-serial adapters...
I'm looking to two alternative usb - serial adapters
the uUSB-MB5 converter
pros :
.Very small (probably it may fit inside the dreamcast)
.TX, RX already at 3.3v levels
Cons:
.No RI signal (according to chaos schematics, its not required for the dc.)
.No external clock signal (although the USB converter supports up to 1 Mbps with hw handshake)
.Its not FTDI based, but there are linux drivers at the manufacturer's website
the Mini USB adapter used for the arduino mini
pros :
.Includes RI signal
.FTDI based
Cons
.TX, RX at 5 v (therefore requiring additional IC to handle the 5 <-> 3.3 conversion)
. it uses a B type USB connector (therefore i will need to carve a bigger hole on the dreamcast for the USB plug)
. no pins for a external clock signal (allthough i may solder it on the pin of the ftdi ic it self, since its a SMD)
I'm looking to two alternative usb - serial adapters
the uUSB-MB5 converter
pros :
.Very small (probably it may fit inside the dreamcast)
.TX, RX already at 3.3v levels
Cons:
.No RI signal (according to chaos schematics, its not required for the dc.)
.No external clock signal (although the USB converter supports up to 1 Mbps with hw handshake)
.Its not FTDI based, but there are linux drivers at the manufacturer's website
That adapter is indeed nice and small. If you don't need the 24MHz clock, then you would only have to add the reset transistor and be good to go.
You could leave a little space to add the oscillator later on...
Also the CP2102 chip used in this adapter should be supported by Linux out of the box, just like the FTDI one.
Jae686 wrote:[*] the Mini USB adapter used for the arduino mini
pros :
.Includes RI signal
.FTDI based
Cons
.TX, RX at 5 v (therefore requiring additional IC to handle the 5 <-> 3.3 conversion)
. it uses a B type USB connector (therefore i will need to carve a bigger hole on the dreamcast for the USB plug)
. no pins for a external clock signal (allthough i may solder it on the pin of the ftdi ic it self, since its a SMD) [/list]
While the connector is bigger, it also sticks out while on the other adapter it is aligned to the board. So you'd have to make the opening big enough to
fit the cable...
If I were to build another one of these, I think I'd go with the smaller adapter and try to fit it all inside the DC
Jae686 wrote:In your circuit what IC you used for the Interface Switiching (buffer tri-state?)
And how did you wired it ?
74VHC244, just like in Chaos's original schematic: http://f17.aaa.livedoor.jp/~takotako/dc ... t232bm.php (3rd schematic, titled "Dreamcast Serial Port Adaptor (for FT232BM base unit)").
The VHC version of this chip allows to interface between 5v and 3.3v logic. It should also work with 3.3v on both sides, but other chips might work as well in that case and be easier to find.